Realistic anatomical phantoms are very useful for many reasons, including but not limited to training of surgeons or other clinicians for practicing medical procedures. For these applications the most useful phantoms are constructed to provide realistic biomechanical properties of actual tissue regions being operated or passed through during the medical procedure. Such a phantom must therefore approximate as close as possible actual tissue being encountered in the procedure, for example, healthy tissue is generally biomechanically different from tumor tissue, when the procedure is tumor resection. Also, in the example of the brain, various sub-anatomical structures within the organ can differ in firmness and their locations and distances from a surgical target can be used to plan the best trajectory to a chosen target. Thus a realistic phantom would contain tissue mimic materials for each type of tissue likely to be encountered during the medical procedure. The different types of tissue/tumor may be characterized by different tissue density, location and orientation. For example tumors are not usually characterized by oriented tissue (as are muscle tissue, ligaments, tendons etc.) and are typically of different density compared to healthy tissue.
One type of anatomical phantom being used are made of cryogel materials. Currently, phantoms produced of cryogel structures containing domains of various density are prepared by producing the different domains separately and assembling these variable density domains together to give a fabricated product containing the multi-density domains. This technique is limiting in that at least one structure prepared from cryogel must go through two freeze thaw cycles (FTC) which limits the minimum rigidity that can be achieved since repeated FTC's increase this property. Thus, currently, a rigid material must be penetrated or cut to allow backfilling with a solution of a different consistency to give a multi-density domain structure in which the resulting structure is characterized by discontinuities or gaps/seams between the different structures. The issues of limited minimum rigidity and discontinuous domains are obstacles to the level of detail that can be achieved.
Accordingly, it would be beneficial to provide a method would allow production of anatomical phantoms having seamless domains of various densities to be produced.